Contraception method using competitive progesterone antagonists and novel compounds useful therein

ABSTRACT

Competitive progesterone antagonists, including two novel steroids, viz., 11β,19-[4-(cyanophenyl)-o-phenylene]-17β-hydroxy-17α-(3-hydroxyprop-1(Z)-enyl)-4-androsten-3-one and 11β,19-[4-(3-pyridinyl)-o-phenylene]-17β-hydroxy-17α-(3-hydroxyprop-1(Z)-enyl)-4-androsten-3-one, inhibit formation of endometrial glands at below their ovulation inhibiting dose and the abortive dose, and thus achieve oral contraception in females without adversely affecting the menstrual cycle and without risk of aborting a previous implanted fertilized egg or a fetus.

BACKGROUND OF THE INVENTION

This invention relates to a novel contraceptive method employing acompetitive progesterone antagonist and to novel progesteroneantagonists useful therein.

By inhibiting the formation of endometrial glands and epithelium growth,the implantation of a fertilized egg in the uterus is renderedimpossible (inhibition of the uterine receptivity). The employment ofcompetitive progesterone antagonists according to the invention can thusbe used for contraception in the female.

RU 486(11β-[4-N,N-(dimethylamino)phenyl]-17β-hydroxy-17α-propinyl-estra-4,9(10)-dien-3-one;EP-A-0057115) and other 11β-aryl or 11β,19-arylene-substituted steroidsare compounds which can displace progesterone and the glucocorticoidsfrom their respective receptors. These substances are pharmacologicallydistinguished by strong progesterone- and glucocorticoid-antagonisticeffects. These properties determine their previously practicedtherapeutic uses. RU 486 is useful, e.g., as a progesterone antagonistfor therapeutic termination of pregnancy and also as a glucocorticoidantagonist for treatment of Cushing's syndrome in the wake of apathologically increased secretory activity of the suprarenal cortex.The abortive dose of RU 486 is 200-600 mg in the female.

It has also long been known that competitive progesterone antagonistsare able to inhibit ovulation in various animal species and in the humanfemale. (Collins et al., “Blockade of the spontaneous mid-cyclegonadotropin surge in monkeys by RU 486; A progesterone antagonist oragonist”, J. Clin. Metab., 63:1270-1276 (1986);

Croxatto, H. B., “Salvatierra 1990 Cyclic use of antigestagens forfertility control”, IIIrd International Symposium on Contraception,Heidelberg, Jun. 19-23, 1990;

Danford et al., “Contraceptive potential of RU 486 by ovulationinhibition. III. Preliminary observations on once weeklyadministration”, Contraception 40: 195-200 (1989);

Kekkonen et al., “Lähteoenmäki P 1990 Interference with ovulation bysequential treatment with the antiprogesterone RU 486 and syntheticprogestin”, Fertil Steril [Fertile Sterile] 53,4747;

Puri et al., “Gonadal and pituitary responses to progesterone antagonistZK 98 299 during the follicular phase of the menstrual cycle in bonnetmonkeys”, Contraception 39, 2: 227-243 (1989);

Puri et al., “Contraceptive potential of a progesterone antagonist ZK 98734: Effect on folliculogenesis, ovulation and corpus luteum function inbonnet monkeys”. In Moudgal et al., (eds) (1990);

U.S. Pat. No. 4,764,513 teaches that the receptivity of the endometriumfor implantation (implantation window) can be shifted (delayed) byadministering a competitive progesterone antagonist to a female toincrease the likelihood of successful implantation of an in vitrofertilized egg.

11β,19-o-Phenylene-bridged steroids, which exhibit especially strongcompetitive progesterone-antagonistic effectiveness in the case ofconsiderably reduced antiglucocorticoid activity relative to thecomparison compound11β-(4-dimethylaminophenyl)-17β-hydroxy-17α-(propin-1-yl)-4,9(10)-estradien-3-one(RU 486; EP-A-0 057 115), are described for the first time in U.S. Pat.No. 5,095,129. The novel compounds of this invention (Compounds I andII) fall within the scope of the generic formula of U.S. Pat. No.5,095,129, but are not disclosed therein by name or by example.

The dose of a competitive progesterone antagonist having an ovulationinhibition effect depends greatly on the species thereof employed. Inthe case of RU 486, it is 50-100 mg in the human female. (Croxatto etal.; loc. cit., Ledge et al. (1992) Inhibition of ovulation using verylow dose mifepristone; Abstract: Second Congress of the European Societyof Contraception. RU 486 shows little or no dissociation of its centraland endometrial effects in humans (Ledge W L et al., Terra Symposium onProgesterone Antagonists, May 25-29, 1992, Mohouk, N.Y.).

An “LH+2” treatment for implantation inhibition has been proposed (Swahnet al., “The effect of RU 486 administration during the early lutealphase on bleeding pattern, hormonal parameters and endometrium,” HumanReproduction 5, 4:402-408 (1990)): 2 days after the LH peak(LH=Luteinizing Hormone) in the menstrual cycle (occurrence of the LHpeak corresponds to the time of ovulation) of the female (i.e., thus onday 14, 15 or 16), an ovulation-inhibiting dose of RU 486 isadministered one time. The active compound is thus administered onlyafter the time of ovulation in the luteal phase of the menstrual cycle(luteal contraception).

It was only recently reported that an endometrial desynchronization inthe female without hormonal changes (progesterone and estradiolconcentrations) can be achieved by the competitive progesteroneantagonist RU 486, when the latter was administered on day 5 and day 8after the occurrence of the LH peak in the menstrual cycle (dosage ineach case 10 mg, peroral) (Kettel et al., 1992). Reliable conceptionwithout ovulation inhibition cannot be achieved if a competitiveprogesterone antagonist is administered only after LH peaks in themenstrual cycle is achieved.

It has now been found that in accordance with this invention,competitive progesterone antagonists are capable, at a dosage regimewhich does not inhibit ovulation or induce abortion, of inhibiting theformation of endometrial glands in the proliferation phase as well asthe function of the glands in the luteal phase of the menstrual cycle,thereby achieving contraception, if the administration of the dose takesplace at least once before and optionally also after the occurrence ofthe LH peak.

SUMMARY OF THE INVENTION

In a method aspect, this invention relates to a method of contraceptionin a female, which comprises administering thereto during the follicularphase of her menstrual cycle and optionally also in the luteal phasethereof an amount of a competitive progesterone antagonist, which isless than an ovulation-inhibiting and less than an abortion-inductivedose and which is effective to inhibit the formation of endometrialglands, which glands are a requirement for the implantation of afertilized egg in the uterus.

In a composition aspect, this invention relates to an11β,19-o-phenylene-17β-hydroxy-17α-(3-hydroxyprop-1(Z)-enyl)-4-androsten-3-oneof the formula:

wherein R is

In another composition aspect, this invention relates to apharmaceutical composition comprising in admixture with apharmaceutically acceptable carrier, an amount per unit dosage of acompetitive progesterone antagonist which is less than anovulation-inhibiting and less than an abortion-inductive dose and whichis effective to inhibit the formation of endometrial glands andepithelium growth.

DETAILED DISCUSSION

In the proliferation phase, an estrogen-induced formation of thesecretory glands in the endometrium occurs in the normal menstrualcycle, while in the luteal phase (also designated as the secretionphase), the secretory activity of the glands is induced by progesterone.The described effect of the competitive progesterone antagonists in theproliferation phase, i.e., before ovulation, thus is not inherentlybased on a progesterone inhibition effect, since the proliferation ofthe endometrial glands is estrogen-dependent. Further, the progesteroneconcentrations in the blood in the proliferation phase of the menstrualcycle are very low. By the use of competitive progesterone antagonistsaccording to the invention, a selective inhibition of the uterinereceptivity is achieved without adversely influencing the menstrualcycle and at doses too low to induce abortion if ovum implant hasalready occurred.

The ability to achieve contraception at lower than abortion-inducingdoses and ovulation inhibiting doses is a very important considerationfor some human females who are opposed to abortion or are concernedabout the long-term medical effects of ovulation inhibition.

A decisive advantage of the use proposed here exists in the very highcontraceptive reliability of the progesterone antagonist employed, sincethe endometrium is not capable to receive a fertilized egg when arespectively very low dosage of the competitive progesterone antagonistis administered before and optionally after the ovulation. Animplantation is also not to be ruled out in the proliferation phase ofthe normal menstrual cycle. Since the endometrial glandular secretionsare essential for endometrial receptivity, a successful implantation isimpossible in the case of an atrophy of the endometrial glands andepithelium. As a result, contraceptive reliability is also assured infemales with an irregular menstrual cycle.

Two novel competitive progesterone antagonists, viz.,11β,19-[4-(4-cyanophenyl)-o-phenylene]-17β-hydroxy-17α-(3-hydroxyprop-1(Z)-enyl)-4-androsten-3-one(I) and11β,19-[4-(3-pyridinyl)-o-phenylene]-17β-hydroxy-17α-(3-hydroxyprop-1(Z)-enyl)-4-androsten-3-one(II)have surprisingly pronounced peripherally selective effectiveness, i.e.,the effect of compounds I and II on the endometrium is very greatlypronounced, while at the same dose, at most only a slight central effectis observed on the hypophysial-ovarian axis.

Such competitive progesterone antagonists can also be designated asdissociated, since at a specific threshold dose, although changes of theendometrium are observed, ovulation (central effect) is not inhibited.The ratio of ovulation-inhibiting dose and implantation inhibiting dose(dissociation factor) (as determined in the rat after peroraladministration) can be used as a measurement of the dissociation. Thisratio varies from species to species but is at least about 30 or higherin a dissociated or competitive progesterone antagonist.

An advantage of dissociated or competitive progesterone antagonists liesin the fact that they can be administered at doses high enough toachieve endometrial effects without inhibiting ovulation. As a result, anormal menstrual cycle is maintained.

The competitive progesterone antagonists are preferably administered asindividual spaced dosage units, e.g., preferably at 4 to 10 days inregular intervals, e.g., every week of the menstrual cycle, each at adose which is insufficient to inhibit ovulation or to induce abortion ifimplantation has already occurred. On the other hand, a similar effecton endometrial receptivity can be achieved with lower once-daily oraldoses. The use of slow release systems (microcrystalline suspensions,transdermal patches and subcutan implants) is also possible, providedthe amount of progesterone antagonist released therefrom is sufficientto inhibit ovum implantation during the predicted life of the system butlower than the dose which interferes with any ovulations which wouldotherwise have occurred during that period of time.

The above-described use of competitive progesterone antagonists isevidenced by tests performed with Onapriston[11β-(4-dimethylaminophenyl)-17α-hydroxy-17β-(3-hydroxy-propyl)-13α-methyl-4,9-gonadien-3-one;EP-A-0129499], a typically competitive progesterone antagonist, onadult, female bonnet monkeys (Macaca radiata).

The test design is set forth below:

bonnet monkeys: adult female animals, body weight 3.5-4.5 kg groupstreated with 5 mg and 10 mg per animal per Onapriston (N = 3): groupsubcutaneously on an oily base (benzyl benzoate/castor oil 1:10)beginning of treat- day 1 of the menstrual cycle, ment and diagram ofthen administration in one- treatment: week intervals duration oftreatment: 2 cycles vehicle control 1 ml (N = 3): collection of blood 1× daily for the first 10 samples: days of the respective menstrual cycleand then every 2 days; also in the pretreat- ment and aftertreatmentcycle endometrial the biopsies were performed histology: under ketamineanesthesia (10 mg/kg of body weight) on day 20 of the second cycle,i.e., after 7 administrations of the progesterone antagonist hormonalprogesterone and estradiol determinations: were determined with aradioimmuno-assay (RIA)

Observations relative to the changes of the endometrium and the hormonelevel:

Table 1 shows that both the length of the cycle and the menstrual periodrelative to the control group are not changed by the treatment accordingto the invention.

The estradiol and progesterone levels clearly show that thefolliculogenesis and ovulation has occurred normally in all animals:normal preovulatory estradiol peak, normal progesterone level in theluteal phase (FIG. 1).

The histology shows that in contrast to control animals, the endometriumwas atrophied in both treatment groups. Especially affected were theendometrial glands: atrophic and inactive glands with an increase of thestromal tissue.

TABLE 1 Effect of the vehicle and of Onapriston on the length of themenstrual cycle (MC) and the menstrual period (MP) of bonnet monkeys*Pretreatment Cycle Treatment Cycle 1 Treatment Cycle 2 After-treatmentCycle Length of Length of Length of Length of Length of Length of Lengthof Length of MC MP MC MP MC MP MC MD (day) (day) (day) (day) (day) (day)(day) (day) Group 1 (Vehicle) 96 27 2 25 3 28 2 27 2 126 25 1 24 2 26 224 2 204 29 3 28 2 30 3 27 3 Group 2 (5 mg/week) 246 26 4 24 2 39 5 27 4232 28 1 27 1 29 1 31 3 250 24 3 26 1 26 1 27 4 Group 3 (10 mg/week) 20826 4 25 3  53* 1 26 4 210 24 2 26 1 25 1 48 1 180 30 3 28 1 28 2 27 3 *2ovulation cycles in which bleeding was slight after the first cycle.

The above-described observations clearly show that competitiveprogesterone antagonists are suitable for contraception (implantationinhibition), at individual doses having a non-ovulation-inhibitingeffect as well as a non-abortive effect in each individual dosage unit,provided the administration of the dosage units takes place before andoptionally also after ovulation within each menstrual cycle.

As competitive progesterone antagonists, all compounds are suitablewhich have a great affinity to the gestagen receptor (progesteronereceptor) and exhibit no gestagen activity of their own. For example,the following steroids are suitable:

11β-[(4-N,N-Dimethylamino)-phenyl]-17β-hydroxy-17α-propinyl-4,9(10)-estradien-3-one(RU-38486),

11β-[(4-N,N-dimethylamino)-phenyl]-17β-hydroxy-18-methyl-17α-propinyl-4,9(10)-estradien-3-oneand

11β-[(4-N,N-dimethylamino)-phenyl]-17aβ-hydroxy-17aα-propinyl-D-homo-4,9(10),16-estratrien-3-one(all disclosed in EP-A-0 057 115);

11β-p-methoxyphenyl-17β-hydroxy-17α-ethinyl-4,9(10)-estradien-3-one(Steroids 37 (1981), 361-382), and

11β-(4-acetylphenyl)-17β-hydroxy-17α-(prop-1-inyl)-4,9(10)-estradien-3-one(EP-A 0 190 759); and

the 11β-aryl-14β-estradienes and estratrienes described in EP-A 0 277676, the 19,11β-bridged steroids, which are the subject of U.S. Pat. No.5,095,129, the 11β-aryl-6-alkyl (or 6-alkenyl or 6-alkinyl)-estradienesand pregnadienes known from EP-A 0 289 073 and the 11β-aryl-7-methyl (or7-ethyl)-estradienes known from EP-A 0 321 010 as well as the 10β-Hsteroids of EP-A 0 404 283. This list is not complete as othercompetitive progesterone antagonists described in the above-mentionedpublications as well as those of publications not mentioned here arealso suitable.

For use according to this invention, especially suitable are thosecompetitive progesterone antagonists which are peripherally selectivelyeffective, i.e., in which the endometrial effect is pronounced, at adose at which at most only a slight central effect is observed on thehypophysial-ovarian axis.

Such competitive progesterone antagonists can also be designated asdissociated, since at a specific threshold dose, changes of theendometrium are observed, but the ovulation (central effect) is notinhibited. The ratio of ovulation-inhibiting and implantation inhibiting(dissociation factor) doses can be used as a measurement for thedissociation. It varies depending on the species and is about 30 or morefor a dissociated competitive progesterone antagonist (in the rat afterperoral administration) to be used according to the invention.

The advantage of dissociated competitive progesterone antagonists beingused according to this invention lies in the fact that they can beadministered at higher doses to ensure achieving the necessaryendometrial effects without ovulation being inhibited; i.e., the“normal” course of the menstrual cycle is maintained.

The competitive progesterone antagonists can be administered, forexample, locally, topically, enterally, transdermally or parenterally.Oral administration is preferred.

For the preferred oral administration, especially tablets, coatedtablets, capsules, pills, suspensions or solutions are suitable, whichcan be produced in the usual way with the additives and vehicles usualin galenicals. For local or topical use, for example, vaginalsuppositories, vaginal gels, implants, vaginal rings or transdermalsystems such as skin plasters are suitable.

A dosage unit typically contains about 0.25 to 50 mg of11β-[(4-N,N-dimethylamino)-phenyl]-17α-hydroxy-17β-(3-hydroxypropyl)-13α-methyl-4,9(10)-gonadien-3-oneor a biologically equivalent amount of another competitive progesteroneantagonist.

If the administration of the pharmaceutical agent produced according tothe invention takes place by an implant, a vaginal ring or a transdermalsystem, these administration systems have to be designed so that thedose of the competitive progesterone antagonist released daily in thisrange is 0.25 to 50 mg.

The dose of a competitive progesterone antagonist to be administeredaccording to the invention is below the ovulation inhibiting as well asabortion-inductive dose range of the progesterone antagonist inquestion.

In general, 0.25-20 mg is administered per one-time dose; especially andspecifically in the use of peripherally selective competitiveprogesterone antagonists, 0.5-50 mg per one-time administration can bedosed, since the peripherally selective substances permit a far higherdosage without resulting in ovulation inhibition. The term, “one-time”dose or administration includes an administration system continuouslyreleasing the competitive progesterone antagonist at a ratecorresponding to a 0.25-20 mg daily dose or a 0.5-50 mg single dose.

Without further elaboration, it is believed that one skilled in the artcan, using the preceding description, utilize the present invention toits fullest extent. The following preferred specific embodiments are,therefore, to be construed as merely illustrative, and not limitative ofthe remainder of the disclosure in any way whatsoever.

In the foregoing and in the following examples, all temperatures are setforth uncorrected in degrees Celsius and unless otherwise indicated, allparts and percentages are by weight.

The entire disclosures of all applications, patents and publications, ifany, cited above and below, and of German priority applications P 42 16003.0 and P 42 16 004.9, are hereby incorporated by reference.

PREPARATIVE EXAMPLE 1

11β,19-[4-(4-Cyanophenyl)-o-phenylene]-17β-hydroxy-17α-(3-hydroxyprop-1(Z)-enyl)-4-androsten-3-one

a)3,3-Dimethyltrimethylenedioxy-11β,19-(4-nonafluoro-butylsulfonyloxy-o-phenylene)-androstane-5α,17β-diol

50 g of3,3-dimethyltrimethylenedioxy-11β,19-(4-hydroxy-o-phenylene)-androstane-5α,17β-diol(Example 18a of PCT application PCT/DE88/00150 whose disclosure isincorporated herein by reference) is dissolved under protective gas in1.75 l of tetrahydrofuran (slightly clouded solution) and mixed at 0° C.with 71.3 ml of n-butyllithium solution (1.6 m in hexane). After 30minutes of stirring, 22.8 ml of1,1,2,2,3,3,4,4,4-nonafluoro-1-butanesulfonyl fluoride (˜90%) isinstilled. After one hour of stirring with ice bath cooling, thereaction mixture is stirred into saturated sodium bicarbonate solutionand intensively stirred for one more hour. Then, after adding ethylacetate, the aqueous phase is separated and extracted several times withethyl acetate. The combined organic phases are washed neutral withsaturated sodium chloride solution, dried on sodium sulfate andconcentrated by evaporation in a vacuum. 90.9 g of the title compound isobtained as crude product. 1.9 g of the thus produced nonaflate(C₄F₉SO₃) is chromatographed on silica gel with a mixture of ethylacetate/hexane. 1.27 g of the pure title compound is obtained as whitefoam.

Melting point: 132-133° C.; [α]_(D) ²²=+15.4° (CHCl₃; c=0.525)

b)3,3-Dimethyltrimethylenedioxy-5α-hydroxy-11β,19-(4-nonafluorobutylsulfonyloxy-o-phenylene)-androstan-17-one

63 g of chromium trioxide is added in portions at 0° C. to a mixture of210 ml of pyridine and 600 ml of methylene chloride. Then, 89 g of thenonaflate produced under a), dissolved in 250 ml of methylene chloride,is instilled at the same temperature. Then, the reaction mixture isheated slowly to room temperature and stirred for 2 hours. Aftercompletion of the stirring, the supernatant phase is decanted and theresidue is washed several times thoroughly with methylene chloride. Thecombined organic phases are substantially freed from the residualinorganic components by washing with 0.5 m sodium hydroxide solution,washed neutral with water, dried on sodium sulfate and concentrated byevaporation in a vacuum (removal of the pyridine by azeotropicdistillation with toluene). By chromatography of the residue on aluminumoxide (neutral, step III) with a mixture of ethyl acetate/hexane, 61.9 gof the title compound is obtained as yellowish foam. Crystallizationfrom ethyl acetate results in 55.7 g.

Melting point: 176-177° C.; [α]_(D) ²²=+25.3° (CHCl₃; c=0.520).

c)3,3-Dimethyltrimethylenedioxy-11β,19-(4-nonafluoro-butylsulfonyloxy-o-phenylene)-17α-[3-(tetrahydropyran-2-yloxy)-prop-1-inyl]-androstane-5α,17β-diol

1 l of absolute tetrahydrofuran is mixed at 0° C. under protective gaswith 73.5 ml of 2-(2-propinyloxy)tetrahydro-2H-pyran. Then, 328 ml of a1.6 m n-butyllithium solution (hexane) is instilled slowly in thissolution without a sizeable temperature increase. After 30 minutes ofstirring, a solution of 50 g of the ketone produced under b), dissolvedin 500 ml of absolute tetrahydrofuran, is slowly instilled with ice bathcooling in this reaction mixture and allowed to stir for 30 moreminutes. Then, the reaction mixture is mixed with saturated ammoniumchloride solution and the aqueous phase is extracted with ethyl acetate.The combined organic phases are washed with sodium chloride solution,dried on sodium sulfate and concentrated by evaporation in a vacuum. Theresidue is chromatographed on aluminum oxide (neutral, step III). 50.3 gof the title compound is obtained as white foam.

d)11β,19-[4-(4-Cyanophenyl)-o-phenylene]-3,3-dimethyltrimethylenedioxy-17α-[3-(tetrahydropyran-2-yloxy)-prop-1-inyl]-androstane-5α,17β-diol

50 g of the nonaflate produced under c) is dissolved in a mixture of 400ml of toluene and 155 ml of ethanol and mixed in succession underprotective gas with 1.44 g of tetrakis(triphenylphosphine)palladium(0),5.33 g of lithium chloride, 78 ml of 2 m sodium carbonate solution and13.1 g of 4-(1,3,2-dioxaborinan-2-yl)benzonitrile. S. Takahashi et al.,Bul. Chem. Soc. Jpn., 62, 3896 (1989). The reaction mixture is thenstirred for 3 hours at an oil bath temperature of 95° C., cooled to roomtemperature and mixed with water and ethyl acetate. The aqueous phase isseparated and extracted with ethyl acetate. The combined organic phasesare dried on sodium sulfate and concentrated by evaporation in a vacuum.The residue is chromatographed on silica gel with a mixture of ethylacetate/hexane. 38 g of the title compound is obtained as yellowishfoam.

[α]_(D) ²²=−36.5° (CHCl₃ , c=0.515)

e)11β,19-[4-(4-Cyanophenyl)-o-phenylene]-17β-hydroxy-17α-(3-hydroxyprop-1-inyl)-4-androsten-3-one

37 g of the ketone acetal produced under d) is dissolved in 950 ml ofacetone and mixed under protective gas with 95 ml of 4 n aqueoushydrochloric acid. After two hours of stirring at 50° C., the reactionmixture is poured on cold saturated sodium bicarbonate solution (basicpH) and most of the acetone is distilled off. After adding methylenechloride, the aqueous phase is separated and extracted several timeswith methylene chloride. The combined organic phases are dried on sodiumsulfate and concentrated by evaporation in a vacuum. The residue ischromatographed on silica gel with a mixture of ethyl acetate/hexane.23.8 g of the title compound is obtained as yellowish foam.

f)11β,19-[4-(4-Cyanophenyl)-o-phenylene]-17β-hydroxy-17α-(3-hydroxyprop-1(Z)-enyl)-4-androsten-3-one

23 g of the propargyl alcohol produced under e) is dissolved underprotective gas in 825 ml of tetrahydrofuran, mixed with 23 ml ofpyridine and hydrogenated using 2.3 g of palladium (10%) on bariumsulfate as catalyst at standard pressure. After absorbing an equivalentof hydrogen (in addition to TLC control!), the reaction mixture isfiltered on Celite, the filter residue is rewashed with tetrahydrofuranand the filtrate is concentrated by evaporation in a vacuum. Thepyridine is removed by azeotropic distillation with toluene. The residueis recrystallized from acetone/tetrahydrofuran and the thus obtainedcrystallizate is recrystallized again from methylene chloride/methanol.14.3 g of the title compound is obtained as white crystallizate.

Melting point: 265-266° C. (under decomposition); [α]_(D) ²²=+117.8°(CHCl₃, c=0.500).

PREPARATIVE EXAMPLE 2

11β,19-[4-(3-Pyridinyl)-o-phenylene]-17β-hydroxy-17α-(3-hydroxyprop-1(Z)-enyl)-4-androsten-3-one

a)11β,19-[4-(3-Pyridinyl)-o-phenylene]-3,3-dimethyl-trimethylenedioxy-17α-[3-(tetrahydropyran-2-yloxy)-prop-1-inyl]-androstane-5α,17β-diol

13.7 g of the nonaflate produced under 1c) is dissolved in a mixture of140 ml of toluene and 70 ml of ethanol and mixed in succession underprotective gas with 877 mg of tetrakis(triphenylphosphine)palladium(0),1.29 g of lithium chloride, 19 ml of 2 m sodium carbonate solution and2.46 g of diethyl(3-pyridinyl)borane. The reaction mixture is thenstirred for 2 hours at an oil bath temperature of 95° C., cooled to roomtemperature and mixed with water and ethyl acetate. The aqueous phase isseparated and extracted with ethyl acetate. The combined organic phasesare dried on sodium sulfate and concentrated by evaporation in a vacuum.The residue is chromatographed on silica gel with a mixture of ethylacetate/hexane. 8.8 g of the title compound is obtained as yellowishfoam.

b)11β,19-[4-(3-Pyridinyl)-o-phenylene]-17β-hydroxy-17α-(3-hydroxyprop-1-inyl)-4-androsten-3-one

8.8 g of the ketone acetal produced under a) is dissolved in 250 ml ofacetone and mixed under protective gas with 5 ml of 4 n aqueoushydrochloric acid. After two hours of stirring at 50° C., the reactionmixture is poured on cold saturated sodium bicarbonate solution (basicpH) and most of the acetone is distilled off. After adding methylenechloride, the aqueous phase is separated and extracted several timeswith methylene chloride. The combined organic phases are dried on sodiumsulfate and concentrated by evaporation in a vacuum. The residue ischromatographed on silica gel with a mixture of ethyl acetate/hexane.5.0 g of the title compound is obtained as yellowish foam.

[α]_(D) ²²=+48.6° (CHCl₃; C=0.530).

c)11β,19-[4-(3-Pyridinyl)-o-phenylene]-17β-hydroxy-17α-(3-hydroxyprop-1(Z)-enyl)-4-androsten-3-one

5 g of the propargyl alcohol produced under b) is dissolved underprotective gas in 200 ml of tetrahydrofuran, mixed with 5 ml of pyridineand hydrogenated using 500 mg of palladium (10%) on barium sulfate ascatalyst at standard pressure. After absorbing an equivalent of hydrogen(in addition to TLC control!), the reaction mixture is filtered onCelite, the filter residue is rewashed with tetrahydrofuran and thefiltrate is concentrated by evaporation in a vacuum. The pyridine isremoved by azeotropic distillation with toluene. The residue ischromatographed on silica gel with a mixture of ethyl acetate/hexane.3.4 g of the title compound is obtained as yellowish foam.Crystallization of ethyl acetate yields 3.12 g of white crystals.

Melting point: 219-221° C.; [α]_(D) ²²=+72.2° (CHCl₃, c=0.505).

FORMULATION EXAMPLE 3

10.0 mg of 11β-[(4-N,N-dimethylamino)-phenyl]-17α-hydroxy-17β-(3-hydroxypropyl)-13α-methyl- 4,9(10)-gonadien-3-one 140.5mg of lactose 69.5 mg of corn starch 2.5 mg of polyvinylpyrrolidone 252.0 mg of aerosil 0.5 mg of magnesium stearate 225.0 mg total weight

Formulate the above composition into 10 mg. tablets for oraladministration in a conventional manner.

For the use of the pharmaceutical agent produced according to theinvention, it is critical that at least one dosage unit is administeredin the follicular phase of the menstrual cycle (before the ovulation)and optionally at least one dosage unit is administered in the lutealphase of the menstrual cycle (after the ovulation).

Preferably, the pharmaceutical agent produced according to the inventionis administered in individual dosage units every to 4 to every 10 days,preferably weekly or the same day, beginning on any day before ovulationoccurs in the first administration menstrual cycle. The time intervalsbetween administration of the individual dosage units preferably areconstant.

Preferably, the pharmaceutical agent according to the invention isadministered once each week, on the same day of the week, for example onMondays (“Monday pill”). By the weekly administration rhythm always onthe same day of the week, a high degree of reliability is assured.However, it is also possible to administer a dosage unit daily, every 2days or every 3 days, either during only the follicular phase oradditionally also in the luteal phase of the menstrual cycle. It is alsopossible to vary the intervals between the administration of theindividual dosage units of the pharmaceutical agent according to theinvention or to administer it constantly from an implanted slow releasevehicle.

To determine the ovulation-inhibiting doses of competitive progesteroneantagonists, the ovulation-inhibiting test described below is performedon the rat; the respective abortively effective doses follow from theknown (e.g., U.S. Pat. No. 5,095,129) rat abortive test.

The determined dissociation factors for Compounds I, II and RU 486 are

Compound Dissociation factor I  >100 II >30 RU 486 <10

For both compounds I and II, it further has been found that withextraordinarily strong antinidatory effectiveness (compound I is stillcompletely implantation-inhibiting effective in the rat at a daily doseof 0.1 mg and compound II at a daily dose of 0.3 mg), they are notsimultaneously antiglucocorticoidally effective. This is seen from thethymolysis test for antiglucocorticoidal effect (EP-A-0 283 428).

The production of compounds I and II takes place according to thesynthesis route described in EP-A-0 283 428 and as is indicated in theexamples below.

Ovulation Inhibition Test on the Rat

Principle of the Method

For detection of ovulation-inhibiting substances, the rat is well-suitedinsofar as it spontaneously ovulates and the cycle can easily beobserved by means of vaginal smears. This makes it possible to controlthe course of the test also during the treatment phase.

METHOD EXAMPLE 4

Test Animals

Female rats weighing 190-210 g, pro dosi 6 animals.

The animals are kept in Macrolon cages in rooms with controlled exposureto light (10 hours of darkness: 14 hours of brightness), fed a standarddiet (pelletized rat food) and tap water at will.

Formulation and Administration of the Test Substance

The test substances are dissolved in benzyl benzoate/castor oil (1+9v/v) and the daily dose is administered in a volume of 0.2 ml s.c.

In the oral application, the test substance is suspended in a carrierliquid (85 mg of Myrj^(®) in 100 ml of 0.9% w/v NaCl solution) and thedaily dose is administered in a volume of 0.5 ml.

Test Batch

Two cycles are observed before the beginning of the test by means ofvaginal smears. Only animals with a regular 4-day cycle are used in thetest. The assignment to the treatment groups takes place at random.Beginning in the metestrus, the test substance is administered over 4days (day 1-4) and the cycle is further controlled.

On day 4 (after the administration), animals, which have an estrus ormetestrus at the time of the vaginal smear, are ovariectomized on oneside under ether anesthesia. Crush preparations are prepared from thetubes and examined by microscope for the presence of egg cells. On day5, all animals (intact and unilaterally ovariectomized) are killed withCO₂ gas and the tubes are prepared and examined in the same way.

METHOD EXAMPLE 5

Evaluation

In the individual dosage groups, the percentage of animals in which theovulation was inhibited is determined.

Volunteers:

Anamnestic condition of patients: Healthy, normocyclic women only.Preferably volunteers after ligation of both fallopian tubes or aftersurgical extirpation of both fallopian tubes (ectopic pregnancies), orwomen only exposed to vasectomized partners.

Human Study 1: Characterization of the biochemical and morphologicalmarker(s) of endometrial receptivity after short-term treatment withonapristone during the luteal phase.

This is a pilot study to establish which biochemical methods, inparticular identification of endometrial marker proteins, are useful inmonitoring further studies with low-dose onapristone (daily andintermittent).

Experimental Protocol:

Groups of Volunteers:

Two groups (control and treatment group) of 8-10 women each.

Duration of the Study:

Evaluation of three cycles: pre-treatment, treatment and post-treatmentcycles.

TREATMENT: 50 mg onapristone/day on days LH+1 and LH+2 orally

This dose of onapristone is known to induce premature menstruation inhumans when given during the late luteal phase. However, according tothe Bygdeman's study (Swahn et al. (1990)), early luteal treatment(LH+2) with a single dose of 200 mg RU 486 does not impair the length ofthe cycle.

EVALUATION: RIA: LH, FSH, E2 and progesterone during the pre-treatment,treatment and post-treatment cycles.

Endometrial biopsy and collection of the uterine fluid on day LH+3 andday LH+8 (treatment cycle) (see Appendix for details)

Occurrence of menstrual bleeding.

Human Study 2: Evaluation of daily application of onapristone onovulation and endometrial morphology and biochemistry: a dose-findingstudy.

a) Objective:

The results of this study identifies a dose of onapristone which doesnot impair the cycle but does exhibit an effect on the morphology andfunction (endometrial marker proteins) of the endometrium. A minimaldose inducing endometrial changes can thus be established.

b) Design of Study:

Groups of volunteers: Four groups (three treatment groups and a controlgroup) of 8-10 women each.

Duration of the study: Evaluation of three cycles: pre-treatment,treatment and post-treatment cycles.

Regimen: 18 daily oral administration of 20 mg (group 1), 10 mg (group2) and 5 mg (group 3) onapristone starting on day 1 of the cycle.

c) Evaluation:

RIA, LH, FSH, E₂ and progesterone and cortisol during the pre-treatment,treatment and post-treatment cycles.

Evaluation of endometrial biopsies and collection of the uterine fluid(by prevical) on day 16 and day 23 of the treatment cycle (see appendixfor details)

Occurrence of menstrual bleeding.

Human Study 3: Effects of once-a-week administration of onapristone onovulation, endometrial morphology and biochemistry

a) Objective:

The results of this study determines a once-a-week dose of onapristonewhich does not impair the cycle but does exhibit an effect on themorphology and function (endometrial marker proteins) of theendometrium.

b) Design of Study:

Groups of volunteers: Four groups (five treatment groups and a controlgroup) of 8-10 women with ligated oviducts.

Duration of the study: Evaluation of four cycles: pre-treatment, twotreatment and post-treatment cycles.

Treatment:

Once-a-week oral administration of 50 mg (group 1) 20 mg (group 2), 10mg (group 3) 2 mg (group 5) and 0.25 mg (group 5), onapristone startingon day 1 of the cycle over the two cycles.

c) Evaluation:

RIA, LH, FSH, E₂ and progesterone during the pre-treatment, treatmentand post-treatment cycles.

Evaluation of endometrial biopsies and collection of the uterine fluidon day 16 and day 23 of both treatment cycles (see appendix fordetails).

Occurrence of menstrual bleeding and cycle abnormalities:

By performing the described treatment scheme, the following is observed:better control of the cycle of the treatment groups compared to thecontrol group; high tolerance; high contraception reliability; andestrogen-free oral contraception.

The preceding examples can be repeated with similar success bysubstituting the generically or specifically described reactants and/oroperating conditions of this invention for those used in the precedingexamples.

From the foregoing description, one skilled in the art can easilyascertain the essential characteristics of this invention, and withoutdeparting from the spirit and scope thereof, can make various changesand modifications of the invention to adapt it to various usages andconditions.

What is claimed is:
 1. A method of implantation inhibition in a female,which comprises administering thereto during her menstrual cycle anamount of a competitive progesterone antagonist, which is less than anovulation-inhibiting dose and less than an abortion-inductive dose.
 2. Amethod according to claim 1, wherein the competitive progesteroneantagonist is administered during both the follicular phase and theluteal phase.
 3. A method according to claim 2, wherein the progesteroneantagonist is administered orally about one weekly during each week ofthe menstrual cycle.
 4. A method according to claim 1, wherein thecompetitive progesterone antagonist is11β-[(4-N,N-Dimethylamino)-phenyl]-17β-hydroxy-17α-propinyl-4,9(10)-estradien-3-one(RU 38486),11β-[(4-N,N-dimethylamino)-phenyl]-17β-hydroxy-18-methyl-17α-propinyl-4,9(10)-estradien-3-one,11β-[(4-N,N-dimethylamino)-phenyl]-17aβ-hydroxy-17aα-propinyl-D-homo-4,9(10),16-estratrien-3-one,11β-p-methoxyphenyl-17β-hydroxy-17α-ethinyl-4,9(10)-estradien-3-one, or11β-(4-acetylphenyl)-17β-hydroxy-17α-(prop-1-inyl)-4,9(10)-estradien-3-one.5. A method according to claim 1, wherein the competitive progesteroneantagonist is11β-(4-Dimethylaminophenyl)-17α-hydroxy-17β-(3-hydroxypropyl)-13α-methyl-4,9-gonadien-3-one,or11β-(4-acetylphenyl)-17β-hydroxy-17α-(3-hydroxyprop-1-enyl)-4,9(10)-estradien-3-one.6. A method according to claim 1, wherein the competitive progesteroneantagonist is11β,19-[4-(cyanophenyl)-o-phenylene]-17β-hydroxy-17α-(3-hydroxyprop-1(Z)-enyl)-4-androsten-3-one,or11β,19-[4-(3-pyridinyl)-o-phenylene]-17β-hydroxy-17α-(3-hydroxyprop-1(Z)-enyl)-4-androsten-3-one.7. A method according to claim 1, wherein the progesterone antagonist isadministered in individual dosage units every 4 to every 10 days,beginning on any day before the day of ovulation of the first menstrualcycle during which the administration occurs.
 8. A method according toclaim 1, wherein the progesterone antagonist is administered orally. 9.A method according to claim 1, wherein the female is a human being. 10.A method according to claim 1, wherein the female is a human being andthe progesterone antagonist is administered thereto orally every week ofeach menstrual cycle during which contraception is desired.
 11. A methodaccording to claim 10, wherein the competitive progesterone antagonistis11β,19-[4-(cyanophenyl)-o-phenylene]-17β-hydroxy-17α-(3-hydroxyprop-1(Z)-enyl)-4-androsten-3-one,or11β,19-[4-(3-pyridinyl)-o-phenylene]-17β-hydroxy-17α-(3-hydroxyprop-1(Z)-enyl)-4-androsten-3-one.12. A pharmaceutical composition comprising an11β,19-[4-(cyanophenyl)-o-phenylene] or11β,19-[4-(3-pyridinyl)-o-phenylene]-17β-hydroxy-17α-(3-hydroxyprop-1(Z)-enyl)-4-androsten-3-oneof the formula

wherein R is

and a pharmaceutically acceptable carrier.
 13. A pharmaceuticalcomposition of claim 12 wherein said compound is11β,19-[4-(cyanophenyl)-o-phenylene]-17β-hydroxy-17α-(3-hydroxyprop-1(Z)-enyl)-4-androsten-3-one.14. A pharmaceutical composition of claim 12 wherein said compound is11β,19-[4-(3-pyridinyl)-o-phenylene]-17β-hydroxy-17α-(3-hydroxyprop-1(Z)-enyl)-4-androsten-3-one.